In a variety of industrial situations it is required to pump gases in order to achieve particular working results. As will be readily appreciated by the skilled person, pumping gases requires special considerations given that a significant proportion of known pump technology was developed for use in connection with liquids that are incompressible for practical purposes.
One such approach to this problem has been the development of vacuum pumps that can lower the internal pressure of the working space by evacuating gases from that working space.
One common type of vacuum pump that has been developed for evacuating gas from a working space is a rotary vane pump that consists of an eccentrically mounted, rotary vane received in an internal pump cavity that has a number of outwardly projecting slots that each slidably receive a vane. In this way, as the rotary hub is rotated, centrifugal force causes the vanes to slide outwardly along the projecting, slots in order to abut the inner surface of the internal pump cavity, creating a gas seal between the vane and the inner surface. As the rotary vane rotates a working space is temporarily created adjacent an orifice, and the compression and expansion of this working space generates a pumping action that is suitable for pumping the gas to (or, in some cases, from) the orifice positioned adjacent the working space.
However, since gases are highly compressible when used as a working fluid it will be readily appreciated that rotary vane vacuum pumps must operate at high rotational speeds and for extended periods (if not continuously) when maintaining a vacuum in an industrial application. These operating conditions can place significant demands on the equipment used to power the pump, which is often an electric motor.
Moreover, in some applications, installation space is limited and therefore it is desirable to include all required hardware (both mechanical and electronic) in a single piece of equipment in order to simplify and streamline the installation of the vacuum pump and minimize the space required for the vacuum pump and all attendant hardware that is required, which of course will depend on the end user application.
Accordingly, there is need for an improved vacuum pump that is robust, adapted for high volume, efficient and continuous operation, is easily installed and adapted for use and installation in restricted spaces.